倒带文件，创建动态结构体 [英] Rewind File, Create Dynamic Struct

问题描述

此功能将倒带文件，创建动态数组（大小），并在数据读取，填充_data结构动态数组。需要注意的是流
按值这个时候过去了。该函数然后返回填充
结构的阵列

this function will rewind file, create the dynamic array (of size), and read in the data, populating the _data struct dynamic array. Note that stream is passed by value this time. The function then returns the populated array of struct

struct _data
{
    char* name;
    long number;
};

struct _data *load(FILE *stream, int size)
{
    struct _data BlackBox = calloc(size, sizeof(_data));

    char tempName[3];

    stream = fopen("names.txt", "r");
    for (int i=0; i<size; i++)
    {
        fscanf(stream, "%s %ld", tempName, &data.number);
        BlackBox[i].name = calloc(strlen(tempName), sizeof(char));
        strcpy(BlackBox[i].name, tempName);
    }
    fclose(stream);

    return &BlackBox;
}

File Content
ron 7774013
jon 7774014

我是初学者和有困难的设计code。有人可以请解释。谢谢

I am a beginner and having difficulty designing the code. Can someone please explain. Thanks

推荐答案

我觉得你有从GCC一定的警示作用来帮助你。

I think you have some warning from gcc to help you.

修复内存管理与释放calloc，不返回堆栈指针

Fix memory management with your calloc, and don't return a stack pointer

typedef struct _data                                                           
{                                                                              
    char* name;                                                                
    long number;                                                               
} _data;                                                                       

_data *load(FILE *stream, int size)                                            
{                                                                              
    _data *BlackBox = calloc(size, sizeof(_data));                             

    char tempName[3];                                                          

    for (int i=0; i<size; i++)                                                 
    {                                                                          
        fscanf(stream, "%s %ld", tempName, &BlackBox[i].number);               
        BlackBox[i].name = strdup(tempName);                                   
    }                                                                          
    fclose(stream);                                                            

    return BlackBox;                                                           
}                                                                              

int main (void)                                                                
{                                                                              
    FILE *f = fopen("test.data", "r");                                         
    _data *data = load(f, 2);                                                  
    printf("%s %ld\n", data[0].name, data[0].number);                          
    printf("%s %ld\n", data[1].name, data[1].number);                          
    return 0;                                                                  
}   

输出

 aurel@vm-pontarlier:~$ ./a.out 
ron 7774013
jon 7774014

考虑变革_data

typedef struct _data{
    char name[256];
    long number;
} _data;

扫描将是：

for (int i=0; i<size; i++)                                                 
{                                                                          
    fscanf(stream, "%s %ld", BlackBox[i].name, &BlackBox[i].number);       
}   

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